As scientists continue to explore the poles as part of the International Polar Year, hoping to better understand the Earth's most extreme environments, some researchers are looking for answers even farther off -- toward the north pole of Mars.

Two years after President Bush proposed to return astronauts to the moon, NASA announced plans Monday for manned trips there by 2020 and the construction of a permanent base, most likely near the Shackleton crater on the moon's south pole,…

The Mars rover Opportunity reached the rim of the Victoria Crater on Mars, capturing new images of a 900-meter depression that could reveal information about the possibility of life on the Red Planet. Principal scientist Steve Squyres discusses the mission's…

NASA's rover Spirit has reached the summit of a bedrock mountain on Mars, and from that vantage point, mission managers will plot the robotic explorer's next move among the numerous intriguing surrounding geologic features.

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